Window sash balance



Oct. 7, 1952 H. B. FORESMAN 2,513,093

wINnow sAsH BALANCE Filed Aug. 23, 194e 2 SHEETS- SHEET 1 ATTORN EY Oct7, 1952 H. B. FoREsMAN WINDOW sAsH BALANCE TSHEET 2 Filed Aug. 25, 19482 SHEETS INVENTOR,

' ATTORNEY FIG. 5

Patented Oct. 7, 1952 UNITED STATES PATENT OFFICE WINDOW sAsH BALANCEHarry B. Foresman, Oklahoma City, Okla Applicata@ Augustzs, i948, serialNq. 45,7416' The present invention relates to` mechanism for adjustablypositioning `vertically slidable window sash, and `more particularly tospring mechanism for retaining such sash in various positions ofvertical adjustment.

The principal object of the present invention, is to provide a springmechanism which will eliminate, or supplant, the conventional sashcords,pulleys, and sash-weights.

` An important object or the present invention is to provide a springtension unit which, wheninstalled, resides on the inside surface of theside member of a window frame, thus making it possible to eliminate theconventional sash weight wells or channels usually built into theexteriors of said side members.

Another object is toprovide a mechanism of this class which is simple toinstall, has few movingparts to become Worn or to get out of order, andwhich is cheap "to manufacture.

A further objectis to providea spring friction device capable 0f beingcompounded to accom modate heavy weight sash;

An additional object is to provide a friction producing loop-typespring, adapted to reside in a vertical channel in the outsideedgesurface of a vertically sliding window sash, said spring capable ofbeing installed upon or removed from the sash without dismounting thesash from the window frame, and without removing any of thev frameslstop-strips.

i Another object is` to provide such spring with resilient reinforcingelements which may be insented within the spring loop in order toincrease itsy friction producing capabilities.

A furtherl object is to provide a spring of this class, which can beused as an anchor for one end of a helical sash lifting spring.

Other objects will be apparent from the following description, whentaken inV conjunction with the `accompanying two sheets of drawings,wherein: i

Figure 1 is an elevational View of a conventional Windcw frame, housingVtwo vertically slidable window sashes, and showing in dotted lines, twoof the devices of the present invention op'eratively installed;

Figure 2 is an enlarged vertical sectional view through one side of theframe and one of the sashes, and illustrating the device of the presentFigure 4 is an enlarged perspective View of one offthe friction springmembers, and also showing a 'reinforcing spring which is adapted to beremovably inserted within the nrst spring member;

4 Claims. (CL mile-76)` 2 v Figure 5 is a view somewhat similar to Fig.3, but illustrating' one of the` friction springs installed without anylifting spring; and,

Figure 6 is a fragmentaryvertical sectional view through the side windowframe member and the `lower portion of a sash, the view illustrating`installation of two of the friction springs and one of the reinforcingsprings.

Like characters of reference designate like parts in those gures of thedrawings in which they occur.

In the drawings:

- The reference numeral I indicates, as a whole,

a conventional window frame having `an upper sash 2 and a lower sash 3slidably mounted be-` tween its twotvertical side members. The twosashes may be of any conventional type `which includes a pair ofvertical side rails 4, a horizontal top rail 5, and ahorizontal bottomrail E.`

The window frame I may ibe of any conventional type, includingahorizontal sill 1, a horizontal topv plate 8,1 and two parallel verticalside members extending between the sill and the plate. The left hand oneof these two Vertical side members is shown in Figs. 2, 3, 5, and 6, andis indicated by the reference numeral 9.

Any suitable mechanism may be provided for balancing the weight of thesashes 2 and 3, for instance,` the conventional sash weight, `sash cord,and pulley could be used, or as shown in Figs. 2 and 3, a helicalretrieving spring I0 may be used for this purpose.

The device of the present invention is for the purpose of providingfrictional tension between the outer edge surface of the side rail ofthe sash, and the inner surface ofthe side member 9, so as to retain thesash in any vertical position. One `of the` devices of the presentinvention may be installed in the lower end of either one or both of theside rails of a sash, or could beim stalled in the upper end ofsuchrail. n

One of the spring tension or friction spring members of the presentinvention is best illustrated in Fig. 4 of the drawings, and isindicated, as` a whole, by the reference numerall. The friction springor element 20 is `formed of a single piece or` strip of strap metalwhich is shaped as shown while in an annealed condition, and whichisthereafter tempered to provide an inherent resiliency tending tolkeepthe strip in its pre-formed shape. l The element 2!) consistssubstantially` of a straight flat end portion 2l which may well betermed as `the bracket, a slightly bent or ofi-set portion 22, and aloop portion 23 which forms a complete convolution. The other endportion of the strip, after the loop is made, continues inside the loopbeyond the off-set portion 22,l and rests upon inside surface of thelower portion of the loop. This latter end portion is indicated by thereference numeral 24, and is free to move along the inside surface ofthe loop portion, should the sides thereof be pressed toward each other.Should the sides of the loop 23 be pressed toward each other, theirinherent resiliency will resist such bending pressure, and the free endportion 24 will act to further resist such pressure. The resistancesupplied by the end portion 24 is considerably greater than thatfurnished by the loop sides, because when the two sides are moved towardeach other, the end portion 24 must eventually deform upwardly. Sincethe end portion 24 is almost straight, and is short in length, it offersmore resistance to deformation than the mere flexing of the two sides ofthe loop.

That portion vof the loop 23 which lies most remote from the free endportion 24 is reduced in width as shown at 25.

In Figs. 2 and 3, the friction member 20 is shown installed in the lowerend of a groove 26 which is formed in the outer edge surface of the siderail 4 of the upper Window sash 2. The element 20 is installed by merelyforcing it upwardly into the groove, and then tacking it in place with anail 21 inserted through a slot 28 in the bracket portion 2l of theelement. The depth of the groove is less than the normal width of theloop 23, and consequently when the element 20 is forced into the groove,its sides are compressed inwardly toward each other. The inherentresilience ofthe loop therefore causes its two sides to exert an outwardpressure against the side member 9 of the window frame, and also againstthe bottom of the groove.

The lower end of the helical spring I is hooked into the upper end ofthe loop 23, and its upper end is attached-to a hook 29 rigidly mountedon the window frame side member 9 adjacent the upper end thereof.

y Ordinarily, one of the elements 2D installed at each lower corner of asash will furnish suiiicient friction with the frame member 9 to holdthe sash in any vertical position to which it is moved. However, if thesash is exceptionally large or heavy, more friction may be necessary.InV order to meet such occasions, an arcuate reinforcing element 30 isprovided.

f The element 30 (Fig. 4), is also made of spring steel, and when in itsnormal form, constitutes an open sided loop as shown. When increasedfriction is desired, one of the elements 3D is compressed and visinserted into the loop 23 of the friction element 20. More than one ofthe reinforcing elements 30 may be used within the loop 23, if desired.

Of course, the friction elements 20 may be similarly installed in thelower ends of the two side rails 4 of the bottom sash 3.

In cases in which sash weights are used to balance the weight of thewindow sash, the grooves 2B are not needed. In such cases, acomparatively short cavity 3l is provided in the lower end of each siderail 4 of the sash, and one of the friction elements 20 is insertedtherein. Such an installation is shown in Figs. 5 and 6.

Fig. 6 illustrates the manner in which two of the'friction elements maybe assembled together and installed so that their resilient energy iscompounded. Since the slot 28 in each bracket 2| is elongated, the nail2l may be inserted through both slots and driven into the sash rail. Oneor more ofthe reinforcing elements 30 may also be used in this doubleinstallation.

From the above description, it is thought to be evident that bycompounding the elements 20 and 3U, sufficient friction may be obtainedto accommodate most window sashes of conventional dimensions andconstruction.

Obviously the invention is susceptible to some change or alterationwithout defeating its practicability, and I therefore do not wish to beconfined to the preferred embodiment shown in the drawings and describedherein, further than I am limited by the scope of the appended claims.

I claim:

1. A spring for producing friction between a window frame and the edgeof a vertically slidable window sash, including: a loop of resilientstrip metal; means for anchoring the loop to the sash; and a loop-likespring element having both its ends free so that they may be telescopedto reduce the normal size of the element, said spring element adapted tobe nested within the first loop to resiliently reinforce the same.

2. A spring for producing friction between a window frame and the edgeof a vertically slidable window sash, including: a loop of resilientstrip metal adapted to nest in a channel formed in said sash edge, andto slidably contact the adjacent surface of the window frame; means'foranchoring said loop in said channel; and a looplike spring elementhaving both of its ends free so that they may be telescoped to reducethe normal size of the element, said spring element adapted to be nestedwithin the first loop to resiliently reinforce the same. i

3. A spring for producing friction between a window frame and the edgeof a vertically slidable window sash to support the sash in the frame,including: a strip of resilient sheet metal bent longitudinally outwardupon itself t0 form a hollow loop with one end of the strip confinedwithin the loop and free to move longitudinally therein to resiliently`reinforce the same; an outwardly extending olf-set portion formed by thestrip and projecting from the loop; and an end portion extendinglaterally from the off-set portion and forming an anchoring bracket forthe strip.

4. A spring for producing sash-supporting friction between a windowframe and the edge of a vertically slidable window sash, including: astrip of resilient sheet metal bent longitudinally outward upon itselfto form a hollow loop with one end of the vstrip conned within the loopand free to move longitudinally therein to resiliently reinforce thesame, said loop adapted to nest in a channel formed in said sash edge;an outwardly extending off-set portion formed by the strip andprojecting from the loop; and an end portion extending laterally fromthe off-set portion along another edge of the sash and forming ananchoring bracket for holding the loop in said sash channel.

' HARRY B. FORESMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 522,626 Suydam July 10, 18941,145,925 Saul July 13, 1915 1,660,071 Draver Feb. 2l, 1928 2,284,343Ricci May 26, 1942

